Mafia 2- This violent gangster simulator has hidden Easter Eggs (objects) throughout the game. Many games have easter eggs, that is not the problem. The problem with this game is that the easter eggs are pin ups of real women in the nude. These are not computer simulated pictures either, they are real pictures which have been programmed and scanned into the game.
Heavy Rain- What would you do to save someone you love? This detective/whodunnit videogame depicts both male and female nudity with some of the most sophisticated computer graphics in video games today.
Red Dead Redemption-This open world western action game is almost a clean game, except that it has one scene of a man and a woman having sex.
L.A. Noire-L.A. Noire, an open world detective game, is one of the most realistic looking games on the market, second only to Heavy Rain. Why is this a problem? Because they depict fully nude females who have been brutally murdered. It is set during the time of (and makes references to) the infamous real life Black Dhalia case in Los Angeles. Some of the murder cases involved fully clothed women, so I ask why was all the nudity necessary?
Saints Row the Third-In this open world Grand Theft Auto like simulator, gamers are allowed to walk around fully nude (with tv editing blurs covering their bodies), and assault people with overly proportioned male body parts.
This is by no means an exhaustive list of the Mature rated games containing sexual content, but they are some of the worst offenders. If you are a parent and you and your child asks about one of these games my suggestion is to stay away.